2010 INFINITI QX56 sensor

C1807 SENSOR 5V MALFUNCTIONSCS-15
< COMPONENT DIAGNOSIS >
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C1807 SENSOR 5V MALFUNCTION
DescriptionINFOID:0000000005148169
The vehicle height sensor operates on a 5 volt referenc e signal from the suspension control unit. The suspen-
sion control unit also provides ground to the height sensor.
DTC LogicINFOID:0000000005148170
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000005148171
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.POWER SUPPLY CIRCUIT CHECK
1. Disconnect height sensor connector C8.
2. Turn the ignition switch ON.
3. Check voltage between the height sensor connector C8 terminal 1 and ground.
Is 5V present?
YES >> System is working normally.
NO >> Check harness or connector for open or short. If OK, replace the suspension control unit. Refer to RSU-26, "
Removal and Installation".
DTC CONSULT-IIIDiagnostic item is detected when ... Probable malfunction location
C1807 SENSOR 5V MALFUNC-
TION Sensor reference voltage is less than 0.8V or
more than 6V for 20 seconds. • Height sensor power/ground supply. Refer to
SCS-18, "
HEIGHT SENSOR : Diagnosis
Procedure".
• Charging system malfunction. Refer to CHG-
8, "Inspection Procedure".
(+)
(-) Voltage
Connector Terminal
C8 1 Ground 5V
ALEIA0026GB
Revision: April 20092010 QX56

SCS-18
< COMPONENT DIAGNOSIS >
POWER SUPPLY AND GROUND CIRCUIT
1.CHECK COMPRESSOR MOTOR RELAY OPRATION
CONSULT-III
1. Disconnect the suspension air compressor connector C9.
2. Turn ignition switch ON.
3. Select "COMPRESSOR" under AIR LEVELIZER active test items.
4. While operating the test item, check voltage at the suspension
air compressor connector C9 terminal 4.
Is battery voltage present?
YES >> GO TO 3.
NO >> GO TO 2.
2.COMPRESSOR MOTOR RELAY POWER SUPPLY CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Disconnect the compressor motor relay connector.
3. Check continuity between compressor motor relay connector E131 (A) terminal 3 and suspension air compressor connector
C9 (B) terminal 4.
4. Check continuity between compressor motor relay connector E131 (A) terminal 3 and ground.
Are the continuity test results as specified?
YES >> Check compressor motor relay. Refer to SCS-20, "Diagnosis Procedure".
NO >> Repair harness or connector.
3.GROUND CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Check continuity between suspension air compressor connector C9 terminals 1 and 3 and ground.
Is continuity present?
YES >> Inspection End.
NO >> Repair harness or connector.
HEIGHT SENSOR
HEIGHT SENSOR : Dia gnosis ProcedureINFOID:0000000005148177
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
(+)
(-)Voltage
Connector Terminal
C9 4Ground Battery Voltage
ALEIA0021GB
AB
Continuity
Connector Terminal Connector Terminal
E131 3 C9 4 Yes
A —Continuity
Connector Terminal
E131 3Ground No
ALEIA0022GB
Connector Terminal —Continuity
C9 1
Ground Yes
3
ALEIA0023GB
Revision: April 20092010 QX56

POWER SUPPLY AND GROUND CIRCUITSCS-19
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1.POWER SUPPLY CIRCUIT CHECK
1. Disconnect height sensor connector C8.
2. Turn the ignition switch ON.
3. Check voltage between the height sensor connector C8 terminal 1 and ground.
Is 5V present?
YES >> GO TO 2.
NO >> Check harness or connector for open or short. If OK, replace the suspension control unit. Refer to RSU-26, "
Removal and Installation".
2.GROUND CIRCUIT CHECK
1. Turn ignition switch OFF.
2. Check continuity between height sensor connector C8 terminal 3 and ground.
Is continuity present?
YES >> Ground circuit is OK.
NO >> Repair harness or connector.
(+) (-) Voltage
Connector Terminal
C8 1 Ground 5V
ALEIA0026GB
Connector Terminal —Continuity
C8 3Ground Yes
ALEIA0029GB
Revision: April 20092010 QX56

HEIGHT SENSOR SIGNAL CIRCUITSCS-23
< COMPONENT DIAGNOSIS >
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HEIGHT SENSOR SIGNAL CIRCUIT
DescriptionINFOID:0000000005148181
Supplies vehicle height input to the suspension control unit.
Component Function CheckINFOID:0000000005148182
1.CHECK HEIGHT SENSOR OPERATION
CONSULT-III
1. Select "HEIGT SEN" of AIR L EVELIZER data monitor test item.
2. While monitoring test item, add or take away weight from the rear of the vehicle. Check that the voltage value changes with vehicle height.
Is the HEIGHT SEN data monitor responding normally?
YES >> Height sensor is operating normally.
NO >> Refer to SCS-23, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148183
Regarding Wiring Diagram information, refer to SCS-29, "Wiring Diagram".
1.CHECK HEIGHT SENSOR POWER AND GROUND SUPPLY
Check height sensor power and ground supply. Refer to SCS-18, "
HEIGHT SENSOR : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK HEIGHT SENSOR SIGNAL CIRCUIT
1. Disconnect suspension control unit connector B3 and height sensor connector C8.
2. Check continuity between suspension control unit connector B3
(A) terminal 3 and height sensor connector C8 (B) terminal 2.
3. Check continuity between display unit harness connector B3 (A) terminal 3 and ground.
Are the continuity results as specified?
YES >> Replace the height sensor. Refer to RSU-27, "Removal and Installation".
NO >> Repair harness or connector. HEIGHT SEN : Voltage changes with vehicle height
AB
Continuity
Connector Terminal Connector Terminal
B33C 82 Y es
A —Contin u it y
Connector Terminal
B3 3Ground No
ALEIA0035GB
Revision: April 20092010 QX56

SCS-28
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
ECU DIAGNOSIS
SUSPENSION CONTROL UNIT
Reference ValueINFOID:0000000005148190
TERMINAL LAYOUT
PHYSICAL VALUES
AWLIA1640ZZ
Terminal
(Wire color) Description
ConditionReference value
(Approx.)
+ – Signal nameInput/
Output
1
(V) Ground Compressor relay output Output Ignition
switch ON Air levelizer raising vehicle
ride height
Battery voltage
3
(W) Ground Height sensor input
InputIgnition
switch
ON —0
.2 V - 4 .8 V
5
(R) Ground VREF output (height sen-
sor)
OutputIgnition
switch ON —5
V
6
(G/R) Ground IGN power supply
InputIgnition
switch ON or
START —
Battery voltage
7
(W/L) Ground BAT power supply
InputIgnition
switch OFF —
Battery voltage
8
(G/W) Ground Diagnostic K-line Input/
Output ——
—
9
(SB) Ground Exhaust valve output Output Ignition
switch ON Air levelizer lowering vehi-
cle ride height (venting)
Battery voltage
10
(BR) Ground Warning lamp output Output Ignition
switch
ON Warning lamp ON
0V
Warning lamp OFF Battery voltage
14
(L) Ground Height sensor ground Output Ignition
switch ON —
Less than 0.2V
15
(BR/W) Ground Generator input
InputIgnition
switch ON Charge light ON
0V
Charge light OFF Battery voltage
16
(B) Ground
Suspension control unit
ground InputIgnition
switch
ON —
Less than 0.2V
Revision: April 20092010 QX56

SCS-34
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
DTC Index
INFOID:0000000005148192
Self-diagnosis results display item
ABEIA0018GB
CONSULT-III display MalfunctionReference page
Vehicle height sensor [C1801] Vehicle height sensor voltage is less than 0.2V or greater than
4.8V for more than 60 seconds. SCS-9,
"DiagnosisProcedure".
Revision: April 20092010 QX56

SUSPENSION CONTROL UNITSCS-35
< ECU DIAGNOSIS >
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Compressor relay [C1802] • Driving transistor for compressor relay is OFF and monitor
voltage continues at a high level for more than 10 seconds.
• Driving transistor for compressor relay is ON and monitor voltage continues at a low level for more than 5 seconds. SCS-10, "DiagnosisProcedure".
Exhaust solenoid [C1803] • Driving transistor for exhaust valve solenoid is OFF and
monitor voltage continues at a high level for more than 10
seconds.
• Driving transistor for exhaust valve solenoid is ON and mon- itor voltage continues at a low level for more than 5 seconds. SCS-11,
"DiagnosisProcedure".
Vehicle height adjusting malfunc-
tion (compressor)[C1804] Continuous compressor relay ON time is more than 120 sec-
onds. SCS-12,
"DiagnosisProcedure".
Vehicle height adjusting malfunc-
tion (exhaust solenoid)[C1805] Continuous exhaust valve solenoid ON time is more than 120
seconds. SCS-13,
"DiagnosisProcedure".
Vehicle height sensor locking mal-
function [C1806] Output sensor voltage variation
±0.02V is more than 100 sec-
onds when vehicle height range is normal. SCS-14, "
Diagnosis Proce-
dure".
Sensor 5V malfunction [C1807] Sensor reference voltage is less than 0.8V or more than 6V for
20 seconds. SCS-15,
"DiagnosisProcedure"
Integral time malfunction by sup-
plying air [C1808]A suspension air compressor ON request has been in effect
for 180 seconds and the suspension air compressor has not
activated during that time. SCS-16,
"DiagnosisProcedure".
Revision: April 20092010 QX56

SCS-36
< SYMPTOM DIAGNOSIS >
SUSPENSION CONTROL SYSTEM
SYMPTOM DIAGNOSIS
SUSPENSION CONTROL SYSTEM
Symptom TableINFOID:0000000005148193
AIR LEVELIZER
SymptomPossible causeReference page
Inoperative • Suspension control unit
• Compressor motor relay
• Suspension air compressorSCS-37, "
Diagnosis Proce-
dure"
System does not raise • Suspension control unit
• Height sensor
• Compressor motor relay
• Suspension air compressor
• Leak in system
• Restriction in systemSCS-38, "Diagnosis Proce-
dure"
System does not lower
• Suspension control unit
• Height sensor
• Compressor motor relay
• Suspension air compressor
• Restriction in systemSCS-39, "Diagnosis Proce-
dure"
CK SUSP indicator lamp always ON with key ON
• CK SUSP indicator la
mp control circuit
• Suspension control unit SCS-26, "Description"
Revision: April 20092010 QX56